Preamble detection using the Wireless Testbench

8 visualizaciones (últimos 30 días)
Giti Dimrov
Giti Dimrov el 27 de En. de 2023
Comentada: Neil MacEwen el 9 de Feb. de 2023
Dear all,
I am trying to use the preamble detection function in Matlab Wireless Testbench, with 2 USRPs N310. In the transmitter side, I generate a baseband signal, wchich I transmit using the transmit function:
transmit(bbtx,signal,"continuous");
stopTransmission(bbtx);
In the receiver side I use the preamble detection function:
recordLen = milliseconds(1000)
timeout = milliseconds(1000)
[data, timestamp, ~, status] = capture(pd,recordLen, timeout);
At the moment, the two USRPs are connected with cable. Unfortunatelly, only once I managed to get the result given in teh attachment, and most of teh time, I do not detect packets. Could you help me understand the problem?
  1 comentario
Jieming Xu
Jieming Xu el 30 de En. de 2023
Hi Giti,
I noticed that you are you baseband transceiver to transmit signals. If possible, please check the transmitter is working properly. You can use internal loopback or transmit and receive by the same devices to check the transmitter works properly.
As you said, the two USRP devices are wired by cables. Please make sure an attenuator is placed between the transmitter and receiver to avoid it damage the RF receiver.
Best regards,
Jieming Xu

Iniciar sesión para comentar.

Respuestas (1)

Jieming Xu
Jieming Xu el 30 de En. de 2023
Hi Giti,
In preamble detector, if you don't receive anything, you can check the thresholding value and correlator output by using: pd.plotThreshold. From the result, you can check and tune the threshold if it is too high or too low.
From you attachment, I saw you are using the plot threshold function. From the picture you provide, I can see very clear peaks for detection, which mean the transmission and receive of the two N310 devices you are using at that time works corretly. The picture shows me the threshold you set is low, which causes many false alarm detection point where there are no peaks.
If it still doesn't work, please tell me which threshold method (fixed, adaptive) you are using. Also with a plotThreshold picture when you cannot make a detection.
  5 comentarios
Neil MacEwen
Neil MacEwen el 2 de Feb. de 2023
Editada: Neil MacEwen el 6 de Feb. de 2023
Hi Giti,
Looking at your spectrum plot, you are correct, the power is very low. We reproduced the same example on our N310 which has antennas connected and see much higher powers at much lower gains. You may want to investigate the hardware you are using (loopback cable + attenuator).
If you have more detailed questions please contact us via our support pages.
Thanks,
Neil
Neil MacEwen
Neil MacEwen el 9 de Feb. de 2023
This was resolved with the connection of antennas on transmit and receive ports for the loopback case.

Iniciar sesión para comentar.

Categorías

Más información sobre Spectrum Monitoring en Help Center y File Exchange.

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by